RPL for skills assessment

Hi,

I have applied for skills assessment with developer programmer anzsco code.

I have 6 1/2 years of IT experience and almost 2 years of onsite experience. I did my bachelor of engineering in EEE 3 years and diploma EEE 3 years after my SSC.

I have been asked to change my application to RPL stating I didn’t meet acs educational requirements. I am suspecting my diploma document is missing with them so replied same to see if this is the cause.

But just what to know in which cases they will ask us to submit under RPL.
Secondly is RPL application positive outcome will also be accepted same like normal skills assessment for PR.